git: 821dec4d56a8 - main - vnode io: request range-locking when pgcache reads are enabled

The branch main has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=821dec4d56a876db56a82cf1dc54a84905b74f5b

commit 821dec4d56a876db56a82cf1dc54a84905b74f5b
Author:     Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2023-08-06 01:23:35 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2023-08-09 03:54:15 +0000

    vnode io: request range-locking when pgcache reads are enabled
    
    PR:     272678
    Sponsored by:   The FreeBSD Foundation
    MFC after:      1 week
    Differential revision:  https://reviews.freebsd.org/D41334
---
 sys/kern/vfs_vnops.c | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/sys/kern/vfs_vnops.c b/sys/kern/vfs_vnops.c
index 83e95731d7c4..c6ca5b9b5120 100644
--- a/sys/kern/vfs_vnops.c
+++ b/sys/kern/vfs_vnops.c
@@ -1443,6 +1443,7 @@ vn_io_fault(struct file *fp, struct uio *uio, struct ucred *active_cred,
 	void *rl_cookie;
 	struct vn_io_fault_args args;
 	int error;
+	bool do_io_fault, do_rangelock;
 
 	doio = uio->uio_rw == UIO_READ ? vn_read : vn_write;
 	vp = fp->f_vnode;
@@ -1464,13 +1465,10 @@ vn_io_fault(struct file *fp, struct uio *uio, struct ucred *active_cred,
 			return (EISDIR);
 	}
 
+	do_io_fault = do_vn_io_fault(vp, uio);
+	do_rangelock = do_io_fault || (vn_irflag_read(vp) & VIRF_PGREAD) != 0;
 	foffset_lock_uio(fp, uio, flags);
-	if (do_vn_io_fault(vp, uio)) {
-		args.kind = VN_IO_FAULT_FOP;
-		args.args.fop_args.fp = fp;
-		args.args.fop_args.doio = doio;
-		args.cred = active_cred;
-		args.flags = flags | FOF_OFFSET;
+	if (do_rangelock) {
 		if (uio->uio_rw == UIO_READ) {
 			rl_cookie = vn_rangelock_rlock(vp, uio->uio_offset,
 			    uio->uio_offset + uio->uio_resid);
@@ -1482,11 +1480,19 @@ vn_io_fault(struct file *fp, struct uio *uio, struct ucred *active_cred,
 			rl_cookie = vn_rangelock_wlock(vp, uio->uio_offset,
 			    uio->uio_offset + uio->uio_resid);
 		}
+	}
+	if (do_io_fault) {
+		args.kind = VN_IO_FAULT_FOP;
+		args.args.fop_args.fp = fp;
+		args.args.fop_args.doio = doio;
+		args.cred = active_cred;
+		args.flags = flags | FOF_OFFSET;
 		error = vn_io_fault1(vp, uio, &args, td);
-		vn_rangelock_unlock(vp, rl_cookie);
 	} else {
 		error = doio(fp, uio, active_cred, flags | FOF_OFFSET, td);
 	}
+	if (do_rangelock)
+		vn_rangelock_unlock(vp, rl_cookie);
 	foffset_unlock_uio(fp, uio, flags);
 	return (error);
 }